Stanley Kubrick is almost universally regarded as one of the great American directors thanks to films like 2001: A Space Odyssey, Full Metal Jacket, Dr. Strangelove, A Clockwork Orange, and The Shining. But while many movie lovers can happily quote or describe in complete detail entire scenes from those films, we all too often forget about Barry Lyndon. Like all of Kubrick’s films, it is completely distinct from everything else in his filmography, a slow-burning period piece that’s still being picked apart by cinephiles today, and continues to grow in esteem year after year.

In honor of the film’s 40th anniversary, here are 11 facts about Barry Lyndon.

1. IT GREW OUT OF STANLEY KUBRICK’S DESIRE TO ADAPT VANITY FAIR.

Kubrick had long been a fan of William Makepeace Thackeray, and at one point had considered adapting his masterpiece Vanity Fair for the screen. Ultimately, Kubrick “decided the story could not be successfully compressed into the relatively short time-span of a feature film,” and abandoned the idea. By the time he got around to Barry Lyndon, though, he’d found the Thackeray work he wanted to film.

2. KUBRICK’S OBSESSION WITH NAPOLEON CAME IN HANDY.

Throughout his career, Kubrick longed to make a film about the life of Napoleon Bonaparte, with whom he was fascinated. It never happened, but the copious amounts of period research he did on Napoleon’s life and times did help him achieve the accuracy he so desired when it came time to make Barry Lyndon.

3. KUBRICK MAINTAINED HIGH LEVELS OF SECRECY TO AVOID THE PRESS.

At the time he made Barry Lyndon, Kubrick was fresh off A Clockwork Orange, a film that generated a tremendous amount of controversy because of its extreme violence. So, when making his next film, Kubrick told the press almost nothing about it, except who it starred. Even co-star Marisa Berenson, who played Lady Lyndon, was initially only told the film was set in the 18th century, and that she should avoid sunlight to achieve the pale complexion necessary for the period.

4. THE FILM’S LOOK WAS HEAVILY INSPIRED BY PERIOD PAINTINGS.

To achieve the film’s elaborate 17th-century compositions, Kubrick and his cinematographer John Alcott looked to the painters of the day for inspirations, specifically Jean-Antoine Watteau, Thomas Gainsborough, and William Hogarth.

5. KUBRICK WAS SO INTENT ON ACCURACY, HE SOUGHT OUT ACTUAL 18TH-CENTURY CLOTHING.

Perhaps more than any other filmmaker, Kubrick is famous for his almost obsessive attention to detail—and Barry Lyndon is a perfect example of that. In addition to ample research on the period in which the film takes place, and lots of art study to get the look right, he sought out actual clothing from the time, which he acquired via museums, so that even the extras looked perfect.

6. KUBRICK GOT SPECIAL LENSES SO HE COULD FILM BY CANDLELIGHT.

All period dramas feature rooms that appear to be lit by candles and oil lamps, but in reality there are usually big lighting rigs just off camera. That wasn’t the case with Barry Lyndon. Kubrick and Alcott wanted to use as little electric light in the production as possible, and went so far as to get special lenses that had been designed for NASA, which he had specially mounted on cameras that could then be used only with those lenses. The super-fast lenses captured rooms lit only by candlelight perfectly, creating a look unlike any other film.

7. THE CAST AND CREW ENDURED A VERY LONG SHOOT (PARTLY BECAUSE OF THOSE CANDLES).

While reminiscing about the film last year, star Ryan O’Neal (Barry Lyndon) recalled that the shoot was “something like 350 days” (a lot of movies don’t make it past 90 days). Why? Well, the reason seems to have been more than just Kubrick’s reputation for perfectionism. According to co-star Leon Vitali (Lord Bullingdon), Kubrick didn’t plan his shots beforehand, preferring instead to see what his actors would do and then build the scene around that. So, “you’d have to go through the scene 10, 15, 20, 30 times while he looked at every possibility with every lens and figured out his first shot.” The candles Kubrick insisted on using to light the interior scenes also caused trouble, because they had to be replaced every time they burned down.

“The problem was that if we didn’t get the take we had to blow all the candles out and start with new ones,” O’Neal said. “And the candles all had three wicks, that was our trick. So it wasn’t easy to blow them out!”

8. THE FILM’S CASTING PRODUCED A LIFELONG WORKING RELATIONSHIP.

When Leon Vitali was cast as the older version of Lord Bullingdon in Barry Lyndon, he probably had no idea that he would continue working with Kubrick for the rest of the director’s life, and beyond. By the time Kubrick was making The Shining, Vitali was his personal assistant, a position he also held on Kubrick’s final two films, Full Metal Jacket and Eyes Wide Shut (he’s also credited as a casting director on both of those films). Even after Kubrick died in 1999, Vitali continued to supervise restoration of the director’s films for DVD releases.

9. THE FILM FEATURES A KUBRICK FAMILY CAMEO.

Kubrick’s daughter Vivian, who would go on to make the famous behind-the-scenes documentary about The Shining a few years later, appears in the magic show scene.

10. KUBRICK WAS SO PARTICULAR ABOUT HOW THE FILM LOOKED THAT HE SENT PROJECTIONISTS INSTRUCTIONS.

Kubrick, ever meticulous, wasn’t content to perfect every aspect of the film’s look in the way he filmed it. He also wanted as much control as possible over how audiences viewed Barry Lyndon, so in 1975 he sent a letter to projectionists showing the film with specific instructions on aspect ratio, lighting, and even what music must be played during the intermission.

11. IT’S ONE OF KUBRICK’S MOST AWARDED FILMS.

After the successes of 2001: A Space Odyssey and A Clockwork Orange, Warner Bros. was eager to let Kubrick make whatever film he wanted next, but Barry Lyndon was a commercial disappointment in the end. Still, that didn’t stop the acclaim. It’s tied with Spartacus for the Kubrick film with the most Oscars, at four (Best Art Direction-Set Decoration, Best Costume Design, Best Cinematography, and Best Musical Score), and in recent years it has enjoyed a kind of critical renaissance, making both the Village Voice’s 100 Best Films of the 20th Century and TIME’s 100 Best Films Since 1923 lists.